To identify alcoholism risk genes, we are collecting and testing for linkage families from three different American Indian populations which are prevalent relatively homogenous and in which alcoholism is highly prevalent. This study also addresses the genetic epidemiology and psychiatric comorbidity of alcoholism in Indians using structured psychiatric interviews of subjects in large families. Two hundred Cheyenne Indians have been clinically evaluated and their cell lines immortalized. At Jemez Pueblo, data and cell lines have been collected for 200 subjects. A study on the Pima Indians is in progress, with 200 members from single family collected and a target family size of 600. A large panel of random polymorphic probes has been typed in Cheyenne alcoholics and controls and genetic linkage analysis is in progress for this group. An analysis of psychiatric comorbidity analysis in Cheyenne Indian alcoholic has been completed.